Shipping containers of the type involved herein have been assembled heretofore at one location by the use of large complex and expensive jigs and fixtures. The method of the present invention enables the container to be assembled on a production line basis thereby avoiding the bottleneck resulting from assembly of an entire container in substantially one location.
The present invention is directed to the method of making large shipping containers of the type which are removably secured to the chassis of a tractor trailer. The method includes producing a rectangular front and rear assembly each having a header and sill connected to corner posts. Each header on each assembly has two locater points in a horizontal plane. Each corner post of each assembly is provided with a locator point in a vertical plane adjacent one end of the corner post. Locater holes are precisely located from external faces of corner posts.
The method of the present invention also includes producing a rectangular roof assembly and a rectangular floor assembly each having two precisely positioned locater points at each end thereof. The thusly described assemblies are joined to form a rectangular box in a manner so that each locater point mates with another locater point. By so doing, the container can be assembled with only eight fasteners to derive the desired external dimensions. Thereafter, the thusly assembled box is moved down the production line and stopped at appropriate locations for further steps which include applying many additional fasteners at areas where jigs are not needed. At a subsequent step, at least one door will be applied to the rear assembly. If desired, further steps may include the finishing of the container such as by painting the same.
Production of large shipping containers in accordance with the present invention can be accomplished at a faster production rate with a smaller investment for jigs and fixtures while at the same time producing a container which more fully complies with the specifications in that it is less likely to be rejected at an inspection station because the size is outside acceptable tolerance sizes.
Other objects and advantages will appear hereinafter.
For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.